:root {
    --primary-color: #0b3c5d;
    --secondary-color: #1d70a2;
    --accent-color: #4a90e2;
    --text-color: #333;
    --light-gray: #e9ecef;
    --dark-gray: #495057;
    --white: #ffffff;
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f8f9fa;
    color: var(--text-color);
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.header {
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--light-gray);
}

.header h1 {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 28px;
    margin-bottom: 8px;
}

.header p {
    color: var(--dark-gray);
    font-size: 16px;
    margin: 0;
}

.content-wrapper {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    background-color: var(--white);
    border-radius: 8px;
    box-shadow: var(--box-shadow);
    padding: 30px;
}

.input-section {
    flex: 1;
    min-width: 300px;
}

.preview-section {
    flex: 1;
    min-width: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: var(--light-gray);
    border-radius: 8px;
    padding: 20px;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark-gray);
}

.form-control {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--light-gray);
    border-radius: 4px;
    font-size: 16px;
    color: var(--text-color);
    box-sizing: border-box;
    transition: border-color 0.3s;
}

.form-control:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
}

.btn {
    padding: 12px 20px;
    border: none;
    border-radius: 4px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: #07293d;
}

.btn-secondary {
    background-color: var(--accent-color);
    color: white;
}

.btn-secondary:hover {
    background-color: #3a80d2;
}

.button-group {
    display: flex;
    gap: 12px;
}

.qrcode-container {
    margin: 20px 0;
    padding: 20px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 240px;
    width: 240px;
}
.qrcode-container {
    margin: 20px 0;
    padding: 15px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: center;
    align-items: center;
    max-width: 100%;
    width: 240px;
    height: 240px;
    box-sizing: border-box;
}

#qrcode {
    max-width: 100%;
    max-height: 100%;
    width: 200px;
    height: 200px;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

#qrcode canvas {
    max-width: 100%;
    max-height: 100%;
    width: 200px;
    height: 200px;
}

.preview-label {
    font-weight: 500;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.footer {
    text-align: center;
    margin-top: 30px;
    padding-top: 20px;
    color: var(--dark-gray);
    font-size: 14px;
}

@media (max-width: 768px) {
    .content-wrapper {
        flex-direction: column;
        padding: 15px;
    }
    
    .input-section, 
    .preview-section {
        min-width: auto;
        width: 100%;
    }
    
    .preview-section {
        padding: 15px;
        box-sizing: border-box;
    }
    
    .app-container {
        padding: 10px;
    }
    
    .button-group {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        margin-bottom: 8px;
    }
}

@media (max-width: 375px) {
    .content-wrapper {
        padding: 10px;
    }
    
    .preview-section {
        padding: 10px;
    }
    
    .qrcode-container {
        width: 180px;
        height: 180px;
        padding: 10px;
        margin: 10px 0;
    }
    
    #qrcode, #qrcode canvas {
        width: 160px;
        height: 160px;
    }
    
    .app-container {
        padding: 10px;
    }
    
    .header h1 {
        font-size: 24px;
    }
    
    .header p {
        font-size: 14px;
    }
}

@media (max-width: 320px) {
    .qrcode-container {
        width: 150px;
        height: 150px;
        padding: 8px;
    }
    
    #qrcode, #qrcode canvas {
        width: 134px;
        height: 134px;
    }
    
    .header h1 {
        font-size: 22px;
    }
    
    .header p {
        font-size: 13px;
    }
}